Method of casting vitreous china or other ceramic substances in slip form and apparatus for performing the method



0a. 27, 1970' w. MCQUEEN SPY 3,536,799

METHOD OF CASTING VITREOUS CHINA OR OTHER CERAMIC SUBSTANCES IN SLIP FORM AND APPARATUS FOR ERFORMING THE METHOD Filed Sept. 8, 1967 #UT 0T 0T 5 Sheets-Sheet 1 i m A a F 2 INVENTOR WILLIAM MCQUEEN SPY BY g /wm z Day/ E ATTORNEYS Oct. 27, 1970 M QUEEN SPY 3,536,799

METHOD OF CASTING VITREOUS CHINA OR OTHER CERAMIC SUBSTANCES IN, SLIP FORM AND APPARATUS-FOR PERFORMING THE METHOD Filed Sept. 8, 1967 3 Sheets-Sheet 2 1T 1T U INVENTOR WILLIAM MCQUEEN SPY ATTORNEYS Oct. 27, I w. M QUEEN SPY.

METHOD OF CASTING VITREOUS CHINA OR OTHER CERAM SUBSTANCES IN SLIP FORM AND APPARATUS FOR PERFORMING THE METHOD 7 3 Sheets-Sheet 5 Filed Sept. 8, 1967 INVENTOR WILLIAM MCQUEEN SPY BY M ATTORNEYS United States Pat ent 3,536,799 METHOD OF CASTING VITREOUS CHINA OR OTHER CERAMIC SUBSTANCES IN SLIP FORM AND APPARATUS FOR PERFORM- ING THE METHOD William McQueen Spy, Barrhead, Scotland, assignor to Ceramic Engineering Limited, Glasgow, Scotland, a corporation of the United Kingdom of Great Britain and Northern Ireland Filed Sept. 8-, 1967, Ser. No. 666,296 Claims priority, application Great Britain, Sept. 8, 1966, 40,162/66 Int. Cl. C04b 33/28; B28b 1/26 US. Cl. 264-86 6 Claims ABSTRACT OF THE DISCLOSURE Method of and apparatus for casting vitreous china or other ceramic substances in slip form such as wash hand basins in which a series of moulds, each consisting of a cover part and a face part, are arranged in an endwise position in a substantially vertical plane in back-to-back relation with adjacent moulds, the horizontal axis of each mould being tilted downwardly towards an inlet in the lowermost part of the mould. Slip is injected into the moulds and flows through the mould during casting to an outlet provided at the highest point of each mould. After casting the face part of the mould is removed in a horizontal plane and the cast article is also removed in a horizontal plane.

BACKGROUND OF THE INVENTION This invention relates to a method of casting vitreous china or other ceramic substances in slip form. More particularly the invention relates to a method of flow casting of ceramic wash hand basins and like articles and to apparatus for performing the method.

In known methods of casting ceramic articles such as wash hand basins a relatively large area of work space is required as the individual moulds have to be handled during the process of casting by moving them on a bench from a horizontal to a vertical plane and vice versa and laying them out along work benches, a process which requires considerable eifort and generally the services of two men.

This handling of the moulds takes place during the assembly of the moulds prior to casting and during the removal of the cast articles from the moulds.

In known methods of casting ceramic wash hand basins the stages are known in the art as boxing up, filling," casting, running off, stiffening up and emptying. When boxing up the two parts of the mould known as the face part and the cover are secured together, the face part being laid horizontally on a bench and the cover being placed on top of the face part. It is also necessary to set up fillers (headers) on the mould, plug run-off holes in the mould and fill the moulds and headers with slip (liquid clay). After the required thickness of clay has cast up it is necessary to remove the headers and clear air inlet holes in the mould and the run-off holes to allow excess slip to" -be run-01f. To facilitate the running-off of the slip it is normal practice to lift and prop the moulds at an angle. A period of time (which may be up to two hours or more) must then elapse to allow the cast article to harden sufficiently to enable it to be removed from the mould without damage.

To remove the cast basins from the mould, clamps which hold the moulds together, are then removed from the moulds and the part of the mould known as the cover is lifted up away from the cast basin, turned through 180 degrees and placed on the bench.

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A seat is then lifted through degrees and placed over the cast basin which is resting on top of the part of the mould known as the face part. I

The face part, cast basin and seat are then lifted through 180 degrees and placed on the bench.

The face part is then lifted up and back through 180 degrees leaving the cast basin on the seat.

The emptying of the cast basins from the moulds requires the services of two operators.

As an alternative to the conventional method of casting wash hand basins various Mechanised systems have been developed.

Differing only in the degree of mechanisation, these systems are generally based on the principle of conveying the moulds past stations, where an operator, or a mechanism, carries out almost exactly the same operations as for the conventional method.

The above known methods of casting ceramic substances in slip form have the disadvantages of requiring a substantial amount of work space to enable the work to be handled, and the attendance of operators throughout the filling, casting and running-oil? cycles.

The present invention is not such a conveyorised system and represents a complete re-appraisal of the casting technique rather than an attempt to mechanise existing methods.

SUMMARY OF THE INVENTION The present invention provides a method of casting vitreous china or other ceramic substances in slip form whereby a much greater density of work can be achieved from a given area of work space than by known methods. The amount of handling of moulds is eliminated or greatly reduced and the use of fillers is eliminated. The function known as filling, casting, running-off and stiffening up may be performed automatically without the attendance of an operator.

A method of casting ceramic articles such as wash hand basins comprises the steps of boxing up at least one mould consisting of at least a cover part and a face part in an endwise position on a vertical plane, injecting a flow of slip through an inlet in the lowennost part of the mould to provide a continuous flow of slip through the mould and out through an outlet in the highest point of the mould, reducing the flow of slip through the mould towards the end of a casting cycle, reversing the flow of slip to run-off excess slip, stopping the flow of slip and allowing the cast article to stiffen up sufliciently to be removed from the mould, subsequently removing the face part from the mould in a horizontal direction and removing the cast article from the face part of the mould in a horizontal plane.

A preferred embodiment of the invention is illustrated in the accompanying drawings in which:

FIG. 1 is a side elevation of series of moulds showing the arrangement during casting cycle;

FIG. 2 is an elevation of the opposite side of the moulds during casting;

FIG. 3 is a side elevation of the moulds during empty- 111G. 4 is an end view of the moulds during casting cyc e;

FIG. 5 is a schematic diagram of an automated layout.

Referring to the drawings the apparatus for performing a preferred method of casting wash basins comprises the provision of a series of moulds denoted generally at 1 each formed in two sections, consisting of a face part 2 and a cover part 3. Each mould being so formed as to be suitable for completing a casting and emptying cycle while arranged on one plane, the moulds 1 being arranged upright on one end thereof inclined towards the face part at an angle as near the vertical plane as is possible, the

angle being determined by the individual design of each article, and in such a manner that the cast basin contracts on to the face part of the mould and away from the cover part so as to remain on the face part when the face part is removed from the cover part. A suitable angle may be in the order of -15 degrees. Defining the surfaces of parts 2 and 3 forming the cavity as the fronts and the opposite surfaces of each of these parts as the backs, the mould parts 2 are arranged in back to back relation in series with part 3 of adjacent moulds. The back of the face part of one mould is joined to the back of the cover part of the adjacent mould to form a unit by a pin 4 insertable in the top of the mould parts so as to allow flexibility between the parts for alignment of the mould faces and at the same time securing the moulds together.

Each mould is arranged on a mould support surface in the form of a carrier 5 which is mounted on a roller system 6 secured to a bench 7 and the bench top is tilted so that the horizontal axis of each mould is inclined across the roller system 6 at an angle suitable for running-off slip from the mould which may be in the order of degrees from the horizontal, the moulds being tilted downwardly towards that side of the mould in which an inlet 8 is provided at the lowermost part of the mould for injection of the slip into the mould and through which slip is run-off.

An outlet is provided at the highest point of the mould on the end opposite from the inlet to enable slip to flow through the mould from the inlet 8. A channel 16 on the outside of each mould communicates with the outlets 15 to direct the slip 14 flowing from the outlets 15 into a trough 17 which runs along the side of the bench and returns the slip to its source.

A slip supply manifold 10 is arranged adjacent the side of the bench on which the inlets 8 are located to supply slip to each of the moulds by way of flexible tubes 9 from the manifold 10 to the inlet 8. The manifold 10 is connected to a supply of slip in a reservoir 11. A variable and reversible flow pump 12 is provided to convey slip from the reservoir 11 to each of the moulds and to return slip from the moulds to the reservoir 11. A control panel 13 is also provided which can be programmed to vary the casting time and duration as required and to control the flow of slip to and from the moulds.

A preferred method of casting ceramic wash hand basins according to the invention consists of boxing up a series of moulds as shown in FIG. 1, connecting the flexible tubes 9 to the inlets 8 and setting the control panel 13 to initiate the flow of slip for a casting and run-01f cycle.

When the casting cycle commences slip flows through the manifold 10 through the inlets 8, the moulds 1 and out through the outlets 15 by way of the channel 16 to the trough 17 where it is returned to its source. During the initial part of the cycle a rapid flow of slip is provided to fill the moulds then the flow is reduced when excess slip flows from the outlets 1'5 and slip continues to flow through the moulds during the casting period. Towards the end of the casting cycle the slip pump 12 slows down to reduce the flow of slip and at the end of the casting cycle the pump stops to stop the flow of slip thus completing the casting cycle.

The run-off cycle then commences by reversal of the pump 12 to run-off excess slip from the moulds. After an appropriate period, in the order of 20 minutes, the pump speeds up to clear the channels of excess slip, a valve closes off the pump thus completing the casting and runoff cycles. A period of time, in the order of 2 hours, is then allowed to elapse to allow the cast basins to become stiff enough to be removed from the moulds.

To remove the basins from the moulds an operator breaks open each mould in turn by moving the face part in a horizontal direction along the bench on the rollers, releasing the cast basin from the face part, and removing the cast basin in a horizontal direction on a seat designed to support the basin upright.

The basin can then be moved on to an adjoining bench for further processing and the next mould is opened. As one mould is opened the preceding one is closed.

A minimum amount of working space is required for opening and closing the moulds in a series since as each mould is emptied and the parts moved in a horizontal direction the space becomes available for the next mould.

The slip may be fed to the moulds by gravity instead of a slip pump, or separate pumps may be provided for delivery and for run-off.

A pump may also be provided to take away the excess slip from the outlet trough.

Basins may also be cast according to the above described method, the outlet however being plugged during casting so that there is no outlet opening and air is driven from the moulds and the pressure of slip is maintained in the moulds until the required thickness of clay has cast. It is then necessary, when running-01f the moulds, to remove by mechanical means air inlet plugs from the top of the moulds.

The operation of filling, casting and running-off excess slip can be automatically actuated by any known means so that the casting, running-off and hardening cycle can 'be performed without an operator in attendance.

In following the method according to the invention it has been found that basins cast with the slip circulating through the mould show desirable characteristics such as a lack of pin holes in the cast and clean flood casts.

What is claimed is:

1. A method of continuous flow casting of articles of vitreous china or other ceramic substances in moulds comprising the steps of: taking a plurality of moulds, each of which includes a face part and a cover part, and wherein the surface of each siad part which forms a part of the interior of the mould cavity is a front and the opposite surface of each said part is a back; arranging the moulds generally upright in a generally horizontally extending line along a support Surface with the back of each face part directly opposing the back of the cover part of the adjacent mould on the support surface; forming the parts into units by connecting together for movement with each other along said support surface the face part of one mould and the said opposing cover part of the adjacent mould such that each unit includes one face part and one cover part which parts are back-to-back with respect to each other; sequentially moving each unit along said line towards an adjacent unit to form complete mould cavities between the fronts of the faces and cover parts which come together as the units are thus moved towards each other; clamping adjacent units together to form complete moulds having mould cavities; injecting a continuous flow of slip through an inlet at the lowermost part of each complete mould such that the slip fiows through the mould and out through an outlet at the highest point of each mould during a casting cycle thereby leaving formed walls of the article in the mould; stopping the flow of slip to the moulds; draining excess slip from the moulds through the inlets while permitting air to enterthe moulds through the said outlets; allowing the cast article to stiffen-up sufiiciently to enable it to be removed from the mould; unclamping the units from each other; while still maintaining the two parts of each unit connected together, sequentially moving each unit in a generally horizontal direction along said line away from an adjacent unit to separate the two facing parts and hence open the mould cavity formed between those two units; retaining the cast article on said face part during opening of that mould cavity; and then extracting the cast article in a generally horizonal direction from the face part of its respective mould.

2. The method of claim 1, wherein the step of extracting the cast article includes retainin the cast article in the same general orientation as during casting by supporting the cast article with a seat while extracting it in said generally horizontal direction from the face part.

3. The method of claim 1, wherein the step of retaining the cast article on the face part includes arranging each mould tilted at an angle of approximately 1 to toward the face part about a generally horizontal axis transverse to said generally horizontal line.

4. The method of claim 1, wherein the overall shape of each mould, viewed in a transverse plane, is generally rectangular, and wherein the steps of injecting and draining slip include tilting the support surface trans versely about an axis generally parallel to the said generally horizontal line and providing said lowermost and uppermost locations of the inlet and outlet, respectively, by locating the inlet and outlet at the lowermost and uppermost corners, respectively, of the tilted rectangular mould.

5. Apparatus for casting articles of vitreous china or other ceramic substances comprising: a plurality of moulds arranged end to end, each mould including a face part and a cover part, and wherein the surfaces of said parts which face each other to form the interior of the mould cavity are fronts and the opposite surfaces of said parts are backs; a support surface, said mould parts being arranged upright and in a generally horizontal line along said support surface with the back of each face part directly opposing the back of the cover part of the adjacent mould; connecting means for connecting together each face part and the said opposing cover part of the adjacent mould such that each unit includes one face part and one cover part which are back-to-back with respect to each other; each group of connected face and cover parts forming a unit which is movably generally horizontally along said support surface; the parts of the units being so connected together and the 'units being arranged with respect to each other such that when a unit is moved toward another unit to form a complete mould cavity between the fronts of the face and cover parts coming together, the front surfaces of the face and cover parts on the opposite side of said moving unit separate from each other to open that mould cavity, each complete mould having an inlet at the lowermost part of the mould for injection of slip into the mould and an outlet for the slip at the highest point of the mould, said mould parts being inclined at an angle of between 1 to 15 from a vertical plane towards the face part about an axis transverse to said line so that when the two parts of a given mould are separated from each other the cast article will remain on the face part at least partially under the influence of gravity prior to being positively removed therefrom.

6. The apparatus of claim 5, wherein the support surface is a roller conveyor.

References Cited UNITED STATES PATENTS 1,600,286 9/ 1926 Lea 26 4-86 1,163,328 12/ 1915 Eckstein 26486 1,703,871 3/ 1929 Curtis 264-86 2,273,015 2/ 1942 Bower 26486 2,803,043 8/ 1957 Stephens 264-86 3,225,414 12/ 1965 Dean 26486 1,914,740 6/ 1933 Greene 2529 FOREIGN PATENTS 298,963 10/ 1963' Japan. 434,494 8/ 1935, Great Britain.

38,776 7/ 1931 France.

JULIUS FROME, Primary Examiner J. H. MILLER, Assistant Examiner US. Cl. X.R. 25--29, 129 

